Japanese scientists have planted sunflower seeds in experimental plots on farmland in three locations near the Fukushima Nuclear Power plant in hopes of reducing radiation from cesium being released into the atmosphere when the power plant was damaged in the March 2011 earthquake.

Space agriculture professor Masamichi Yamashita at the Japan Aerospace Exploration Agency (JAXA) who is leading the experiment says that radioactive cesium is similar to kalium, which is used in agricultural fertilizer.

As the sunflowers grow it is theorized that they will utilize the cesium and remove it from the soil, thereby decontaminating it so that the land can once again be used for cultivating crops. Similarly, sunflowers were planted to decontaminate toxic soil after the 1986 Chernobyl nuclear accident.

Reported levels of radiation one meter above the ground at the experimental sites is fairly high, ranging from 7 to 21 microsieverts per hour, but the seeds have sprouted and are growing. "If we can verify that sunflowers absorb cesium efficiently, we want to expand the area for growing sunflowers," said Yamashita.

Once the sunflowers have absorbed the radioactive cesium, they must be disposed of. Burning the sunflowers is not an option because the cesium would likely be dispersed into the atmosphere. Yamashita and other researchers have come up with another solution and are planning to use bacteria to decompose the sunflowers and reduce the volume of the plants and treat them as radioactive waste.